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US 8,310,307 B2Granted
Amplifying circuit
AssigneeOnkyo Corporation
InventorsTsuyoshi Kawaguchi, Mamoru Sekiya, Yu Takehara, Norimasa Kitagawa
Life of this patent
Estimating the term…
Abstract
The first emitter follower circuit and the second emitter follower circuit can increase an input impedance on the side of the inverting input terminal in the amplifying circuit. As a result, when a feedback circuit is connected between the inverting input terminal and the output terminal of the amplifying circuit, a fluctuation in a gain of the amplifying circuit according to a configuration of the feedback circuit can be suppressed.
Claims10
An amplifying circuit comprising:
- a first stage amplifying circuit for amplifying a first input signal to be input into an inverting input terminal and a second input signal to be input into a non-inverting input terminal, and for outputting a first stage amplification signal, wherein
- the first stage amplifying circuit includes
- a first transistor forming a first emitter follower circuit whose input is a positive component of the first input signal, a predetermined first potential being applied to a collector of the first transistor,
- a second transistor forming a second emitter follower circuit whose input is a negative component of the first input signal, a predetermined second potential being applied to a collector of the second transistor,
- a third transistor forming a third emitter follower circuit whose input is a positive component of the second input signal, a predetermined third potential being applied to a collector of the third transistor,
- a fourth transistor forming a fourth emitter follower circuit whose input is a negative component of the second input signal, a predetermined fourth potential being applied to a collector of the fourth transistor,
- a fifth transistor having an emitter to be connected to an output of the first emitter follower circuit, a base to be connected to an output of the third emitter follower circuit, and a collector to which an electric potential of a positive power source is applied via a first collector resistor and from which a positive component of the first stage amplification signal is output, and
- a sixth transistor having an emitter to be connected to an output of the second emitter follower circuit, a base to be connected to an output of the fourth emitter follower circuit, and a collector to which an electric potential of a negative power source is applied via a second collector resistor and from which a negative component of the first stage amplification signal is output.
5 more elements
An amplifying circuit comprising:
- a first stage amplifying circuit for amplifying a first input signal to be input into an inverting input terminal and a second input signal to be input into a non-inverting input terminal and outputting a first stage amplification signal, wherein
- the first stage amplifying circuit includes
- a first transistor forming a first emitter follower circuit whose input is a positive component of the second input signal, a predetermined first potential being applied to a collector of the first transistor,
- a second transistor forming a second emitter follower circuit whose input is a negative component of the second input signal, a predetermined second potential being applied to a collector of the second transistor,
- a third transistor having an emitter to be connected to the emitter of the first transistor,
- a fourth transistor having an emitter to be connected to the emitter of the second transistor,
- a first resistor connected between a collector of the third transistor and a base of the third transistor,
- a second resistor connected between the base of the third transistor and a base of the fourth transistor,
- a third resistor connected between a collector of the fourth transistor and the base of the fourth transistor,
- a fifth transistor having an emitter to which a positive component of the first input signal is input, a base to be connected to the collector of the third transistor, and a collector to which an electric potential of a positive power source is applied via a first collector resistor and from which a positive component of the first stage amplification signal is output, and
- a sixth transistor having an emitter into which a negative component of the first input signal is input, a base to be connected to a collector of the fourth transistor and a collector to which an electric potential of a negative power source is applied via a second collector resistor and from which a negative component of the first stage amplification signal is output.
8 more elements
Dependencies are inferred from the claim text.